The University of Missouri Electron Microscopy Core facility provides the only electron microscopy services and instrumentation for research on the University of Missouri campus. It is through this Core Facility that the major user group performs research that requires transmission electron microscopy. The transmission electron microscope (TEM) currently in the Core Facility was acquired approximately 20 years ago. We have been informed by the manufacturer that new replacement parts are no longer available for this instrument. The instrument continues to be serviced with used parts, but once the supply of any critical part is exhausted, the instrument could soon become nonfunctional. In addition, the existing microscope does not have some features available on newer instruments that are needed by the user group. The objective of this application is to replace the old instrument with a modern TEM that can be equipped with features that will meet the research needs of the major user group and other NIH-funded investigators over the coming 15 to 20 years. The great majority of TEM use in the Core is for NIH-funded research. Core TEM services are currently used to support research on diabetes, aging, cardiovascular disease, nutrition, neurodegenerative disorders, and a variety of other health problems. The time is near when the TEM presently housed in the Core will no longer be able to be serviced. In the absence of a reliable supply of replacement parts, the risk of losing TEM capability altogether is high. The requested TEM will be housed in the existing Core Facility and will be maintained by experienced Core staff. Core staff will supervise use of the instrument under the direction of a Faculty Coordinator for Electron Microscopy Services in consultation with a user Advisory Committee. Training in instrument use will be provided by Core staff and associated faculty. Staff salaries will continue to be provided from a combination of user fees and University funds. A service contract will be maintained with the manufacturer to provide service for the instrument that cannot be performed by Core staff. Service contract costs will be covered by user fees and an institutional subsidy if necessary. The instrument will be available to users outside of the major user group under essentially the same terms that apply to major user group. Broadening the user base will help make the cost per user of maintaining the instrument as low as possible. [unreadable] [unreadable]